Aelian, On Animals 13. 23 (trans. Scholfield) (Greek natural history C2nd A.D.) :
"Now in the course of examining and investigating these subjects and what bears upon them, to the utmost limit, with all the zeal that I could command, I have ascertained that the Skolopendra is a Ketos (Sea-Monster), and of Sea-Monsters it is the biggest, and if cast up on the shore no one would have the courage to look at it. And those who are expert in marine matters say that they have seen them floating and that they extend the whole of their head above the sea, exposing hairs of immense length protruding from their nostrils, and the tail is flat and resembles that of a crayfish. And at times the rest of their body is to be seen floating on the surface, and its bulk is comparable to a full-sized trireme. And they swim with numerous feet in line on either side as though they were rowing themselves (though the expression is somewhat harsh) with tholepins hung alongside. So those who have experience in these matters say that the surge corresponds with a gentle murmur, and their statement convinces me."